import time
import random
import csv
import os
import sys

sys.setrecursionlimit(30000)

def ll_insert(head, name, phone):
    curr = head
    while curr is not None:
        if curr['name'] == name:
            curr['phone'] = phone
            return head
        curr = curr['next']
    new_node = {'name': name, 'phone': phone, 'next': head}
    return new_node


def ll_find(head, name):
    curr = head
    while curr is not None:
        if curr['name'] == name:
            return curr['phone']
        curr = curr['next']
    return None


def ll_delete(head, name):
    if head is None:
        return None
    if head['name'] == name:
        return head['next']
    prev = head
    curr = head['next']
    while curr is not None:
        if curr['name'] == name:
            prev['next'] = curr['next']
            return head
        prev = curr
        curr = curr['next']
    return head


def ll_list_all(head):
    entries = []
    curr = head
    while curr is not None:
        entries.append((curr['name'], curr['phone']))
        curr = curr['next']
    entries.sort(key=lambda x: x[0])
    return entries

    def _hash(name, bucket_count):
    h = 0
    for ch in name:
        h = (h * 31 + ord(ch)) % bucket_count
    return h


def ht_create(bucket_count=2000):
    return [None] * bucket_count


def ht_insert(buckets, name, phone):
    idx = _hash(name, len(buckets))
    buckets[idx] = ll_insert(buckets[idx], name, phone)


def ht_find(buckets, name):
    idx = _hash(name, len(buckets))
    return ll_find(buckets[idx], name)


def ht_delete(buckets, name):
    idx = _hash(name, len(buckets))
    buckets[idx] = ll_delete(buckets[idx], name)


def ht_list_all(buckets):
    entries = []
    for head in buckets:
        curr = head
        while curr is not None:
            entries.append((curr['name'], curr['phone']))
            curr = curr['next']
    entries.sort(key=lambda x: x[0])
    return entries